1. Field of the Invention
The present invention relates to an image forming method in which ink is ejected using an ink jet method to form an image.
2. Description of the Related Art
As a recording medium for ink jet printing, various recording mediums have been examined, and above all, a technique for forming high quality image is required. In ink, various ink substrates have been examined from the viewpoints of water resistance, light-fastness, and the like.
For example, a pigment is used as a colorant that is one of the components contained in ink substrates, and the pigment is dispersed for use in a medium such as water. When the pigment is dispersed for use, dispersion particle diameter in dispersing, stability after dispersing, uniformity in size, and ejection performance from an ejecting head are important, and techniques for improving them have been examined.
Meanwhile, unlike a case of forming an image on a recording medium having porosity such as normal paper and having relative satisfactory absorptivity of ink, even when an image is formed using a non-porous substrate such as polyester as the recording medium, it is preferable drying can be performed quickly after the ink droplets are ejected, fixability, image quality and the like are satisfactory, and an image without stickiness can be obtained after drying.
Concerning the circumstances, printing ink including a colorant and resin and containing a solid component that is solid in an ink at 25° C., a liquid component that is liquid in an ink at 25° C. with a boiling point higher than that of water, and water is disclosed, and it is considered that there is no problem with the drying speed (e.g., Japanese Patent Application Laid-Open (JA-P) No. 2008-101192). As the liquid component, a wetting agent with a high boiling point of 230° C. or higher, and specifically, glycerin, 1,3-butanediol, 3-methyl-1,3-butanediol, 2-pyrrolidinone, and N-methyl-2-pyrrolidinone are disclosed.
In addition, ink jet ink, which includes an aqueous liquid vehicle including a volatile cosolvent having a boiling point of 285° or lower, and a pigment colorant in which acid-functionalized polymer colloid particles dispersed in the liquid vehicle and polymers are coupled, is disclosed (e.g., JP-A No. 2005-220352), and it is considered that the ink has an excellent adhesive property for non-porous substrates.
An aqueous ink composition, which contains resin emulsion having a glass transition temperature of 30° C. or higher in which kinds of monomers such as acryl acid are polymerized, pigment dispersion liquid allows a dispersion polymer to contain a pigment and is rendered dispersible in water, and triethylene glycol monobutyl ether, is disclosed (e.g., JP-A No. 2007-277330), and the ink which can simultaneously achieve dispersion stability (storage stability) and excellent printing quality.